Goddard Yanina A, Vold Robert L, Cross Jennifer, Espe Matthew P, Hoatson Gina L
Department of Applied Science, College of William and Mary, Williamsburg, VA 23187-8795, USA.
J Chem Phys. 2005 Feb 1;122(5):54901. doi: 10.1063/1.1829034.
Solid state deuteron magic angle spinning nuclear magnetic resonance spectra of conductive ring-deuterated polyaniline consist of two peaks, one at the same chemical shift as the insulating form of the polymer and the second shifted by 5.8+/-1 ppm. The magnitude of the shift is field and temperature independent and is identified as a Knight shift. The deuterons undergoing a Knight shift originate from both the crystalline and amorphous regions of the sample, implying that conduction is mediated by delocalized polarons in both these regions. Spin count experiments demonstrate that in highly conductive samples, signal is lost not only by dephasing due to the proximity of localized unpaired electrons but also to high rf reflectance.
导电环氘代聚苯胺的固态氘核魔角旋转核磁共振谱由两个峰组成，一个峰的化学位移与聚合物绝缘形式的化学位移相同，另一个峰的化学位移偏移了5.8±1 ppm。该偏移的大小与磁场和温度无关，被确定为奈特位移。经历奈特位移的氘核来自样品的结晶区和非晶区，这意味着在这两个区域中传导都是由离域极化子介导的。自旋计数实验表明，在高导电样品中，信号不仅会因局部未配对电子的接近而发生相移而损失，还会因高射频反射率而损失。
